This invention generally relates to motor vehicle suspension components and, more particularly, to a steering knuckle assembly including a stamped steering knuckle housing with an attached steering arm link.
Conventionally steering knuckle assemblies are constructed with one-piece forged or cast housings. Attached to these integral units are wheel bearing carriers, torque arms, disc-type brake calipers, ball joints, struts, steering links and other suspension components. Although conventional steering knuckles perform satisfactorily, it is desirable to optimize production costs and enhance structural characteristics in the steering knuckle design.
It is particularly desirable to reduce the weight of the steering knuckle assembly. Weight reductions in this area are advantageous since they reduce both the total vehicle weight and the suspension unsprung mass. Reductions in unsprung mass are themselves desirable since they provide significant improvements in the ride and handling of the vehicle. Overall, weight reductions help to improve both performance and fuel efficiency in the vehicle. As in all manufacturing processes, it is always desirable to provide for an improved steering knuckle assembly which can be produced at a cost savings over current designs.
In reducing weight, and simplicity of construction, one advance has been the production of concave, shell shaped steering knuckle housings, preferably manufactured using metal stamping processes. Such stamped steering knuckles are disclosed in U.S. Pat. Nos. 4,618,159 and 4,722,540 and U.S. Pat. application Ser. No. 579,369, all of which have been assigned to the assignee of the present application and which are hereby incorporated by reference. Stamped steering knuckle housings are often reinforced with one or more internally disposed plates and are further provided with mounting bushings for the various suspension components. Often, the reinforcing plates and the mounting bushings are welded to the stamped housing.
When compared to a conventional steering knuckle design, the stamped composite structure provides a significant weight advantage, primarily due to the use of the stamped components. The use of stamped components also reduces the total cost of the knuckle assembly because of reduced tooling requirements for stamped metal parts as compared to tooling requirements for casting and machining operations.
Additional desirable improvements in a stamped steering knuckle assembly are provided by this invention. In accordance with the preferred embodiment of this invention, a steering knuckle housing is formed by metal stamping processes. The stamping process produces an integrally formed steering knuckle housing having an open shell configuration with a pair of generally opposed side walls and a transverse wall extending therebetween. A steering arm link is mounted to the steering knuckle housing so as to bridge the gap or channel between the opposing sidewalls. The steering arm link operates as a truss or support member extending across the gap and provides the steering knuckle assembly with a box-like, closed construction that further enhances the structural integrity of the assembly. With an interest toward further reducing the weight of the steering knuckle assembly, the steering arm link is integrally constructed. In particular, the steering arm link is provided in solid wire form.
The steering arm link is mounted to flanges which extend off of the opposing side walls of the knuckle housing and includes a side portion which extends to one side of the knuckle housing. This extension forms an attachment point for the steering arm. By bridging the gap between the side walls of the stamped steering knuckle housing, the steering knuckle assembly of the present invention is capable of handling increased torsional and bending loads.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings.